0
\$\begingroup\$

I'm trying to wrap my head around how I need to go about balancing charging a few NiMh battery packs.

I'm using a HiTec x4 charger, which supports balancing charging up to 6 cells at a time. However, the battery packs I'm working with have 12 cells welded together in series. 12 x 1.2v cells, for a total of 14.4v (actually ~17v fully charged).

I attempted to connect the 6 charging leads to the positive ends of the last 6 cells (closest to overall negative), and the 1 negative lead to the overall negative of the pack. However, this causes the charger to throw a 'Connection break' error, which I'm assuming is caused by the other 6 cells, even though they 'sit behind' the cells I'm attempting to balance charge?

How should I go about balance charging these 12 cell packs with a 6 cell balance charger, given I'm not able to break the weld without damaging them? Should I connect the positives leads to every other cell, and balance charge them as 6 x 2.4v "cells" instead? My worry with that is the charger might damage the cells, as it's expecting 1.2v NiMh cells, and I'm giving it 2.4v cells instead.

Any ideas?

Thanks in advance.

\$\endgroup\$
1
\$\begingroup\$

I've just come to learn that NiMh batteries don't need to be balanced in the way that Li-Po or Li-ion battery do. Essentially, to balance the cells you just have to slow-charge at around C/10 for a good 14-15hrs. This works because NiMh cells don't get damaged while slow-charging, even once full. This will eventually bring all the cells up to the same voltage.

Also, my charger was throwing the Connection break error because I had the wires connected the wrong way. Once I figured that out, I realized that the charge settings were wrong anyway, and I wasn't really 'Balance charging'. It turns out the charger only shows the balanced charging option when the 'Li-Po' battery type is selected. shrug

Now onto slow-charging the packs.

\$\endgroup\$

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Not the answer you're looking for? Browse other questions tagged or ask your own question.